media: coda: request to skip kernel mapping for decoded buffers

The kernel driver never touches the decoded buffers with the CPU.
All accesses are either done by hardware DMA masters or userspace
mapping the buffers. This means we don't need a kernel virtual
address mapping for those buffers at all. As those buffers are
usually quite large, we can save a good deal of kernel vmalloc
space by requesting to not have a kernel mapping set up for them.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
index 834f11fe9dc2944bceb219de82a84f03eb3d8b8e..287dc1692286c6ae02729d98a73864914d4fb7a4 100644 (file)
--- a/drivers/media/platform/coda/coda-common.c
+++ b/drivers/media/platform/coda/coda-common.c
@@ -2387,6 +2387,7 @@ int coda_decoder_queue_init(void *priv, struct vb2_queue *src_vq,
 
        dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        dst_vq->io_modes = VB2_DMABUF | VB2_MMAP;
+       dst_vq->dma_attrs = DMA_ATTR_NO_KERNEL_MAPPING;
        dst_vq->mem_ops = &vb2_dma_contig_memops;
 
        return coda_queue_init(priv, dst_vq);